
% two-column multicolumn, centred.
\newcommand{\mcc}[1]{\multicolumn{2}{c}{#1}}
\newcommand{\mcl}[1]{\multicolumn{2}{l}{#1}}
% three-column multicolumn, centred.
\newcommand{\mccc}[1]{\multicolumn{3}{c}{#1}}

\iflandscape{
\begin{table*}[ht]
\begin{center}
\begin{tabular}{
c	r@{.}l 		r@{~/~}l		*5{r@{~}l}
}
\toprule
{}	& \mcc{}	& \mcc{}		&
\multicolumn{2}{b{1.5cm}}{\multirow{2}{1.5cm}{\centering Typical slipknot}} &
\multicolumn{8}{c}{Earth to:} \\
\cmidrule{8-15}
{} & \mcc{}	& \mcc{Range, days}	&
\mcc{} &
\mcc{Moon}	& \mcc{Mars}	& \mcc{Pluto}	& \mcc{Oort Cloud} \\
V-shift & \mcc{Acc (G)}	& normal&extended	& \mcc{5AU} &
.4&Gm		& .5&AU		& 30&AU		&   1&ly \\
\midrule
0	& 0&01		& 130	& 520		&  65&d. &
34&h.	&  17&d.	& 180&d.	&   40&y. \\
1	& 0&1		& 40	& 160		&  20&d. &
11&h.	& 5.5&d.	&  56&d.	& 12.5&y. \\
2	& 0&5		& 18	& 72		&   9&d. &
5&h.	&  60&h.	&  25&d.	&  5.5&y. \\
3	& 1&0		& 13	& 52		& 6.5&d. &
3.5&h.	&  48&h.	&  18&d.	&    4&y. \\
4	& 1&5		& 10	& 40		&   5&d. &
3&h.	&  34&h.	&  14&d.	&    3&y. \\
5	& 2&0		& 9	& 36		& 4.5&d. &
2.5&h.	&  29&h.	&  12&d.	&  2.8&y. \\
6	& 3&0		& 8	& 32		&   4&d. &
2&h.	&  24&h.	&  10&d.	&  2.3&y. \\
\bottomrule \\
\end{tabular}

\begin{tabular}{*2{r@{~=~~}l}}
\mcl{Units of time}	& \mcl{Units of distance} \\
h.	& Hours		& AU	& Astronomical Unit \\
d.	& Days		& Gm	& Gigametre, 1 million kilometres \\
y.	& Years		& ly	& Light-year
\end{tabular}
\end{center}
\caption{Intersystem Travel Times}
\label{tab:intersystem-travel-times}
\vfil
\end{table*}
}{
\begin{table*}[ht]
\begin{center}
\begin{tabular}{rr*7r}
\toprule
V-shift
&&	0 &	1 &	2 &	3 &	4 &	5 &	6 \\
Acceleration & (G)
&	0.01 &	0.1 &	0.5 &	1.0 &	1.5 &	2.0 &	3.0 \\
\midrule
&&				\multicolumn{7}{l}{Range, days}\\
\midrule
Normal
&&	130 &	40 &	18 &	13 &	10 &	9 &	8 \\
Extended
&&	520 &	160 &	72 &	52 &	40 &	36 &	32  \\
\midrule
Destination &	&	\multicolumn{7}{l}{Travel time} \\
\midrule
typical slipknot & 5AU
&	65 d &	20 d &	9 d &	6.5 d &	5 d &	4.5 d &	4 d \\
Earth -- Moon & .4Gm
&	34 h &	11 h &	5 h &	3.5 h &	3 h &	2.5 h &	2 h \\
Earth -- Mars & .5AU
&	17 d &	5.5 d &	60 h &	48 h &	34 h &	29 h &	24 h \\
Earth -- Pluto & 30AU
&	6 m &	56 d &	25 d &	18 d &	14 d &	12 d &	10 d \\
Oort Cloud & 1ly
&	40 y &	12.5 y&	5.5 y &	4 y &	3 y &	2.8 y &	2.3 y \\
\bottomrule\\
\end{tabular}

\begin{tabular}{*2{r@{~=~~}l}}
\mcl{Units of time}	& \mcl{Units of distance} \\
h.	& Hours		& AU	& Astronomical Unit \\
d.	& Days		& Gm	& Gigametre, 1 million kilometres \\
m.	& Months	& ly	& Light-year \\
y.	& Years
\end{tabular}
\end{center}
\caption{Intersystem Travel Times}
\label{tab:intersystem-travel-times}
\vfil
\end{table*}
}